Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Bearing unit, production method therefor and spindle motor

a technology of bearing unit and spindle motor, which is applied in the direction of bearing unit rigid support, sliding contact bearing, mechanical apparatus, etc., can solve the problems of reduced thickness of motor, increased number of parts, and complicated structure, and achieves the shape and size of the grooves that are precisely obtained, not easily loosened, and easy to work.

Inactive Publication Date: 2005-02-08
HITACHI POWDERED METALS COMPANY +1
View PDF6 Cites 19 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a spindle motor with improved fitting performance between a rotating shaft and a bearing, and reduced wear and precise rotation. This is achieved by using a bearing unit with a sintered metal in which magnetic powder is dispersed and sealed by impregnation with a resin. The bearing unit has pores on its surface sealed by the resin, which acts as a lubricant and restrains loose of magnetic powder. The bearing surface also has grooves for generating dynamic pressure. The production method involves compacting a metallic raw material powder mixed with magnetic powder, sintering the green compact, impregnating resin into pores, and then magnetizing the bearing. The spindle motor includes the bearing unit and a rotating shaft supported by the bearing unit.

Problems solved by technology

Such a bearing unit is suitable for HDDs in which oil leakage is not desirable.
However, the structure in which a magnet is located in a bearing results in an increase of number of parts and a complicated structure, and this is not desirable for the reduction of thickness of motors.
In the sintered bearing containing a magnetic powder, relatively hard magnetic powder exists on a bearing surface, and the rotating shaft is not easy to fit thereto and tends to wear easily.
Furthermore, the magnetic powder existing on the bearing surface is loosened by wear, and the loosened particles function as an abrasive between the rotating shaft and the bearing.
As a result, wear is promoted and vibration characteristics are not stable, precise rotation is not obtained.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Bearing unit, production method therefor and spindle motor
  • Bearing unit, production method therefor and spindle motor
  • Bearing unit, production method therefor and spindle motor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

Embodiments in which the invention is applied to HDD motors will be explained with reference to the drawings hereinafter.

FIG. 1 shows a cross section of a spindle motor. The spindle motor is adapted to rotate two magnetic disks D, and comprises a case 10, a bearing unit 20, a rotating shaft 30 rotatably supported by the bearing unit 20, a motor 40, and a hub 50 which supports the magnetic disk D and is rotated by the action of the motor.

A cylindrical holder 11 protruding upwardly in FIG. 1 is formed at the center of the case 10, and the bearing unit 20 is accommodated therein. As shown in FIG. 2, the bearing unit 20 consists of a cylindrical housing 90, a disk-shaped thrust plate 70 which closes the lower aperture of the housing 90, and a cylindrical bearing 60 accommodated in the housing 90. The thrust plate 70 is fitted into a peripheral recess 91 formed at the inner edge of the lower side of the housing 90, and is secured thereto by means such as caulking, welding, adhering, or t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
weight %aaaaaaaaaa
dynamic pressureaaaaaaaaaa
magneticaaaaaaaaaa
Login to View More

Abstract

A bearing unit comprises a bearing 60 formed of a sintered metal in which a magnetized magnetic powder is dispersed in its matrix and at least pores exposed on a bearing surface thereof are sealed by impregnation with a resin; a non-magnetic housing 90 accommodating the bearing 60; and a lubricating fluid M made of a magnetic fluid.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to spindle motors mounted in, for example, information devices or acoustic devices which require precise rotation, relates to bearing units installed in such spindle motors, and relates to production methods therefor, and in particular relates to techniques to be used in HDDs (hard disk drives) in magnetic disk units.2. Related ArtAs precise rotation motors used in, for example, HDDs, there have been provided constructions in which a disk is rotated with high precision by a brushless dynamotor. Bearings suitable for these motors comprise a combination of a radial bearing and a thrust bearing respectively supporting the radial load and thrust load of the rotating shaft. These bearings are generally fluid dynamic bearings in which the rotating shaft is supported with high precision due to the dynamic pressure action of a lubricating oil.Lubricating oils have generally been generally used as lubricating f...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(United States)
IPC IPC(8): F16C33/04F16C33/10F16C17/10F16C33/14F16C33/20F16C35/02H02K7/08H02K15/14
CPCF16C17/026F16C33/107F16C33/1035Y10T29/49639
Inventor TAKEHANA, TOSHIKAZUTOKUSHIMA, HIDEKAZUSHIKATA, HIDEONII, KATSUTOSHIHIROSE, JUN
Owner HITACHI POWDERED METALS COMPANY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com